Can HBOT Heal Ischemic Wounds?

A new study in Diabetes Care found that hyperbaric oxygen therapy (HBOT) did not facilitate significant wound healing for patients with ischemic wounds but those who completed a course of HBOT had significantly fewer amputations and higher amputation-free survival.  

As part of the randomized study, 120 patients with diabetes with ischemic wounds received either the standard of care or HBOT. In the HBOT group, the authors noted 53 patients achieved limb salvage in comparison to 47 patients who received standard of care. After 12 months, 30 index wounds had healed in patients receiving HBOT in comparison to 28 wounds in the standard of care group.

Enoch T. Huang, MD, MPH&TM, FACEP, FUHMS, FACCWS, believes HBOT does have a role in limb salvage and wound healing, and maintains that HBOT addresses the fundamental pathophysiological problems of wound ischemia and hypoxia. Noting that patient selection and timing are key, he has found HBOT has the greatest benefit in the acute, hypermetabolic state following surgical debridement of an infected or ischemic foot, but that HBOT has less benefit when tissue ischemia has resulted in tissue necrosis.

“To make a blanket statement that all patients with a diabetic foot ulcer require HBOT is inaccurate as are assertions that no patients with a diabetic foot ulcer would benefit from HBOT,” asserts Dr. Huang, the Medical Director of Hyperbaric Medicine and Chronic Wound Clinic at Legacy Emanuel Medical Center in Portland, Ore.    

As Dr. Huang notes, the 2015 Undersea and Hyperbaric Medical Society Clinical Practice Guideline recommended against using HBOT for Wagner grade 2 diabetic foot ulcers (DFU) yet the Diabetes Care study includes a significant percentage of patients with a Wagner 2 DFU. He adds that the guidelines also suggest that patients with a serious foot infection who required urgent surgical debridement would benefit from urgent HBOT rather than waiting a mandatory 30 days. Dr. Huang also notes that a per protocol analysis (albeit underpowered) in the study would show that those patients who did complete HBOT did have a higher percentage of amputation-free survival.

David Swain, DPM, CWSP, says HBOT is effective in ischemic wounds as an adjunctive therapy, citing research that patients with periwound transcutaneous oximetry of more than 10 mmHg have a higher potential to heal utilizing HBOT than those with less than 10 mmHg. Therefore, he says if there is some arterial flow to the wound area, it appears HBOT will enhance healing. Hyperbaric oxygen therapy will not help with healing if the tissue has not had adequate revascularization or if there is any infection that has not been treated and/or controlled, cautions Dr. Swain, the Medical Director of the St. Vincent’s Wound Care and Hyperbaric Center at St. Vincent’s Southside Hospital in Jacksonville, Fla.

Dr. Swain has found the level of evidence to be moderate for the use of HBOT for diabetic foot ulcers, crush injuries and soft tissue infections. He calls for more research on what level of tissue perfusion is necessary, pre- and post-dive, to benefit from HBOT.

“Unfortunately, many of the currently published trials have small sample sizes, questionable methodology and inconsistent treatment protocols,” notes Dr. Swain.

Dr. Huang advocates focusing future research on identifying the subgroup of patients with ischemic wounds that may benefit from HBOT as well as focusing on studies that use more appropriate grading systems than the Wagner grading system.

Study Finds Mixed Results Comparing Open And Percutaneous Hammertoe Surgery

By Brian McCurdy, Managing Editor

Percutaneous hammertoe surgery leads to slightly fewer infections but an increased rate of impaired healing in comparison to open surgery with Kirschner wire fixation, according to a recently published study.

The study, published in Foot and Ankle Specialist, focused on 675 hammertoes in 352 patients. The study authors note the K-wire fixation group had resection arthroplasty of the proximal interphalangeal joint while the percutaneous technique consisted of diaphyseal osteotomy of the middle and proximal phalanges combined with tendon release. In the open surgery group with K-wire fixation, the authors note 5.5 percent had pin migrations, 4.5 percent had infections and 3 percent had impaired wound healing. In the percutaneous group, the study acknowledges complications such as impaired healing in 18.4 percent of the patients and 2.3 percent of patients having an infection.

William Fishco, DPM, FACFAS, will fixate hammertoe repairs most often with a K-wire.

“In 20 years of practice, I can say that it is very rare that there is a complication encountered with traditional open resection of the proximal interphalangeal joint with K-wire fixation,” maintains Dr. Fishco, a faculty member of the Podiatry Institute, who is in private practice in Phoenix.

Dr. Fishco will use intramedullary fixation devices for hammertoes but rarely uses intramedullary fixation devices on complex multiplanar toe deformities. He also avoids intramedullary fixation in the fourth toe, saying there is typically an adductovarus deformity component that will undermine fixation, and prefers K-wires in these cases.

The advantages of K-wires are their simple use and familiarity, the ability to fixate multiple joints, cost-effectiveness, and leaving no retained hardware after the toe heals, according to Dr. Fishco. Disadvantages include patients’ fear of pushing the wire into the toe with stubbing, snagging the wire and pulling it out, or pin tract infections that are very rare, according to Dr. Fishco. He also cites an inability to yield any compression or anti-rotation, and notes that intramedullary devices can potentially address both of those issues.

Percutaneous hammertoe correction is advantageous for high-risk surgical candidates, such as geriatric patients and/or patients with poorly controlled diabetes who may have comorbid conditions that would not be suitable for prolonged surgery times and/or general anesthesia, notes Dr. Fishco. He says disadvantages of percutaneous surgical correction include a lack of precise anatomic alignment to create a rectus toe and increased risks for malunion of the toe, and blood vessel or nerve injury.

Combined Fixation Technique May Facilitate Improved First MPJ Fusion

By Brian McCurdy, Managing Editor

A recent study in the Journal of Foot and Ankle Surgery proposes a fixation technique for first metatarsophalangeal joint (MPJ) fusion that combines a Steinmann pin with Kirschner wires.

The study authors reviewed 64 first MPJ fusions on 60 patients using an intramedullary Steinmann pin across the interphalangeal joint with crossing K-wires at a mean follow-up of 27 months. The study notes fusion occurred in 90.6 percent of patients with a 9 percent rate of hallux interphalangeal joint degeneration, only a few of whom were symptomatic.

Study lead author Lawrence Karlock, DPM, says the fusion technique is advantageous for patients who have osteopenic/osteoporotic bone.

“Sometimes in these cases, because of poor bone stock, plate and/or screw fixation may not be amenable for the correction/fusion,” says Dr. Karlock, the Clinical Instructor for the Ohio Podiatric Residency Program with Steward Health Care in Youngstown, Ohio. “In this case, this easy, low cost technique has the advantages for patients in whom standard AO fixation may not be appropriate.”

One disadvantage of the technique is that it does not provide any compression across the fusion site, according to Dr. Karlock. However, he notes that compression is not necessarily needed to obtain fusion as long as one has a safe construct. Dr. Karlock recommends this first MPJ technique in any patient population and says patients can bear weight early due to the stability of the construct.

“Once this technology is utilized, the surgeon would be pleasantly surprised how stable the construct is intraoperatively,” says Dr. Karlock.